Ah -- December, 2006. That explains it. I had some rather extreme things going on in my life at that point and wasn't in as good a position to take note of the outside world as I usually am... *sigh*...

-the other Doug

Really...? Honestly, I've seen so many launches and landings, they tend to blur together. I simply recalled that STS-123 was the first night launch since Columbia, based on the CAIB's strong reccommendation that all launches allow full telescopic coverage and observation so that any foam loss events could be observed (and, therefore, all launches were to occur in daylight). I also recalled that Shuttle flights have tended to a given scheduling -- night launched missions tend to land at night, day launched missions tend to land during the day.

Now that you mention it, though, I also recall that STS-115 was given an OK to land just after dark as a means of extending the flight and giving it greater operational flexibility. I didn't recall the RTF mission landing at night, though...

-the other Doug

The exhaust from the APUs is essentially invisible in normal light, that's why you never notice it on images of daytime landings. But it's a very hot exhaust, so it shows up like a whale's plume on the IR cameras they use for night landings.

I have to remind myself that this is the first night Shuttle landing in more than five years...

-the other Doug

At the STS-123 post-landing press conference, Mike Griffin was asked about the MER situation and about Stern's resignation. I won't even try to paraphrase from memory what Griffin said, but the gist of it was that, first, he had tried to talk Stern into staying. "I didn't see any reason why he had to leave," is what I believe Griffin said about it. But he said that Stern disagreed, and so Griffin accepted it and allowed Stern to resign.

He then said that the letter to JPL announcing the MER and Odyssey budget cuts had not been run past him, had not been reviewed by him, and had not been approved by him. He said that if he had been consulted, there would never have been any kind of dust-up because the letter never would have gone out. Griffin said rather strongly that he doesn't approve of shutting down working spacecraft that are still returning good data.

-the other Doug

I still enjoy comparing these 90-sol missions with the "these things are nuclear, they'll run for years" Viking landers.

Viking 1 lander lifetime: 2247 sols
Viking 2 lander lifetime: 1283 sols
Total Viking lander lifetime: 3530 sols

And at present:

Spirit lifetime: 1501 sols
Opportunity lifetime: 1480 sols
Total MER lifetime: 2981 sols

We're only 550 total sols (275 combined sols) away from the MERs racking up more active lifetime on the surface of Mars than the Viking landers. So, on Spirit sol 1776 and Oppy sol 1755, we'll *really* have something to celebrate. Assuming both of our girls are still rolling then.

Of course, each rover individually has exceeded Viking 2's lifetime already.

-the other Doug

Not so much anymore, but the losses of Mariners 3 and 8 really proved out the concept. In fact, the only dual spacecraft I can recall that were both lost were the Mars penetrators that hitched a ride with MPL.

-the other Doug

Well -- what's wrong with the idea of a lander attached to a balloon? That way you can reconnoiter a lot of landscape with instruments on both the lander and the balloon, and only drop the lander when it's over an area you recognize as a good one for surface exploration. Yes, you run the risk of flying over a unique area and recognizing it as such only after it's passed on by beneath you, but Titan has so many different types of terrain and chemistry to offer, and so much of most of them, I'd think you'd be able to recognize a good area in time to set up the drop.

As for the drop, all you really need is a good parachute system. The lander can be dropped on a chute from 1,000 to 5,000 meters and make a nice, safe landing in that thick air.

-the other Doug

Ooops! Thanks, Dan! That's what I get for setting up a blog after work on a Friday...

-the other Doug

Well, I finally got motivated to become a blogger. I decided that there needs to be a voice amongst political progressives such as myself in favor of manned and unmanned space exploration. And since I can't and won't get into any such discussions here, it just made sense to me to create a blog for the purpose:

http://progressivesforspace.blogspot.com/

I'll be discussing a lot of aspects of space exploration, from my own unique perspective. And I hope to have a significant amount of non-political content, too. For example, I've been itching to publish a nitpick review of the HBO miniseries "From the Earth to the Moon" for quite some time...

Once again, I won't get into any political discussions here... this is not the appropriate forum for that. I hope to have a little something for everyone, though. So, drop by if you like.

-the other Doug

p.s. -- here's hoping this shameless self-promotion isn't offensive to anyone. I figure, if you don't care for me or the points of view I've expressed here, you certainly don't have to come look at my blog... *smile*... But all are welcome.

They're both splendid indirect self-portraits. Both with aesthetically pleasing backgrounds. Of course, the one will remind you of the other...

Seriously, these images give you a feeling of "being there," and are therefore both attractive to the eye and memorable.

-the other Doug

That new image is a really interesting one, Phil. Not only are there a lot of extensional graben, there are many different flow features. The main flows in which the majority of the fresh-looking graben are cut have definite flow boundaries along the lower left of the image, trending up and to the left.

The most interesting thing to my eye are the filled-in grabens as you approach the large dark-rim-ray crater in the upper right. If you look carefully, you can see hints of a lava flow front overlaying the main, cracked flow that makes up a majority of the scene. It is above and to the right of this subtle flow front that we see a number of filled-in and "ghost" graben.

So... there must have been lava flows in Caloris *after* the uplift that formed the graben. That's *very* interesting...

-the other Doug

Name a Europa lander after ACC? After he specifically told us to attempt no landings there???



-the other Doug

I will point out that, in the first 20 minutes of the flight, the word "leak" was used three times when the RCS issue was discussed. Not by PAO, either -- by Houston.

-the other Doug

That looked like a high cloud deck to me, too -- but I will point out that it appeared just before the crew got the call-out about an RCS leak condition. While it's most likely it was a high cloud deck, it could possibly have been a minor dump of RCS fuel.

-the other Doug

A "left RCS issue" is possibly being caused by a bad card in an electronics box. Endeavour is on orbit -- but may have a few operational constraints, here.

-the other Doug

Well -- not a completely nominal launch, here. Right at the throttle-up Go point, Capcom called up that there was "no action" on RCS error lights that were coming on in the cabin, saying "we'll talk about them later." And well prior to orbital insertion, the crew got instructed to begin a malfunction procedure to "recover" the flash evaporator system. PAO says all cooling systems are in good shape, but you don't initiate a mal procedure for the fun of it...

Also, immediately prior to MECO, they got a call that they were Go for the plus-X maneuver and No-Go for the pitch maneuver. RCS problems?

And BTW -- the final minute of insertion through orbiter sep from the ET Cam vantage are absolutely stunning!!!

-the other Doug

And even then, we were wildly optimistic... Kemp was not only a washed-up old spacefarer, he had also been the first man on Mars. Washed up by 2021...

Fine, fun little film.

-the other Doug

Pretty launch, but very, very short time of tracking due to low clouds.

Sounds like everything is working fine, though.

-the other Doug

My goodness, Stu! It almost looks like we're all the way to the bottom of the crater!

I have to say, when I looked at that picture, what instantly came into my mind was "We is low, and we is down among 'em, Charlie!"



-the other Doug

I will say that, on geological timescales, a thousand years and ten thousand years are within the same order of magnitude. And I would imagine that the timing of the loss of magnetic field has a lot to do with how long such a Greenhouse Mars could persist -- without a magnetic field, volatiles (including water, broken down into hydrogen and oxygen) in the upper atmosphere are sputtered off into space far more quickly. The atmospheric water vapor content, which drives the water cycle, would be steadily eroded when the protective magnetic shield collapsed -- but could have reached a comfortable equilibrium while the field was in place.

In any event, my "gut" feeling, here, is that the landscape would probably look rather similar today had Greenhouse Mars lasted for a thousand years or a quarter of a million.

The way in which this whole speculation relates to the question of biogenesis, of course, is whether or not life could develop during the geological instant in which Greenhouse Mars could have existed, and could extremophile descendants have adapted to the conditions that followed? Single-cell organisms seem to have developed on Earth within a very short timeframe after conditions allowed it -- were the "relatively wet and warm" period(s) on Mars long enough to allow for biogenesis?

That's one reason I have a strong desire to find paleobacteria on Mars -- if life could start there under the rather more extreme duress than it found on Earth, well, the implications are profound...

-the other Doug

Just to re-state a bit... in my initial post, I did say that Mars was incontrovertibly once warm and wet *enough* for water to form sinuous, meandering (and sometimes braided) river channels, and to allow for catastrophic floods. That's all I really said. Not that it was that warm and wet for billions of years -- just that it was warm and wet *enough*, for long enough, to allow the features we see to have formed.

I do find it fascinating that, when confronting this fact, those who are belief-level-certain that Mars has always been cold and dry (just as it is today) seem driven to ask themselves how such conditions could be generated on extremely short time scales, such as hours or days, to allow such things to have happened without challenging their dearly-held beliefs. And postulating that impacts had to have both stripped Mars' atmosphere and, *at the same time*, thickened it for brief periods.

I'm not saying that these are impossible scenarios. I'm just saying that my own reaction to them is they "feel" like they push Occam's Razor quite far in order to account for observed features which cannot be created on the Mars they are just certain must always have existed...



For what it's worth, I completely agree that Mars does indeed seem to have been as cold and dry as it is now since the beginning of the lava piling that resulted in the Tharsis Bulge, since those lavas have never been broken down chemically by abundant liquid water. My own opinion is that Mars' magnetic field died as a result of LHB interactions and that its atmosphere, thinned by the LHB to just above a "line" where liquid water was commonly possible, fairly quickly became depleted by solar wind interactions (within a few million years) to where the only further erosion Mars would see from that point on was aeolian- and impact-related. The very last water erosion was probably the catastrophic flooding, set off when frozen reserves of water (and very cold reserves of liquid brine) were mobilized by the heat of the magma rising into the Tharsis region. So, in my own personal perspective, the lavas which define the end of a Mars wet and warm enough for liquid water to be a major erosional factor were actually responsible for the final era of such aqueous erosion.

-the other Doug

Exactly what I was thinking, Dan -- dried-up mud beds.

And, if I might add, they look somewhat freshly dried up. The abundance of craters into the most recently "applied" surface seems negligible to nonexistant. Yes, this surface covers over some older craters, but almost no craters have been punched into it.

Of course, I don't know how large of an area this image covers... if it's small enough, the lack of observed craters isn't that statistically meaningful.

-the other Doug

Wonderful! Assuming the "death plunge" is played live on NASA-TV, I'll have the honor of repeating Wally Schirra's classic line, shouted out as the astronauts watched a film made of Ranger VII's descent images:

"Pull up, you fool! Pull up!!!"



-the other Doug

Well... I completely agree with you (especially with that proviso "largely"), as far as Mars' southern hemisphere is concerned. But north of the dichotomy line (which isn't exactly equatorial), very few remnants of the LHB are seen to survive. That land *has* been heavily resurfaced, somehow, since the LHB.

So -- *half* of Mars fits your description above. Half doesn't.

Makes it deucedly difficult to come up with generalized descriptions of the planet's past, doesn't it?

-the other Doug

Obviously, I'd do 'Neutron Star' as the pilot episode. Heck, you could do an awful lot of good stuff if you just limited the series to Beowulf Schaeffer stories, use him as a series narrator as well as its primary hero.

But I'd love to see something more free-form, where you could slip in earlier stuff, like 'World of Ptaavs,' and even start your series chronology on the Pak world itself. You just don't need to present it all in rigid chronological order, is all... *grin*...

-the other Doug